XnView Software

Well... yes, that would be great! Instant zoom to 100% with LMB down, back to original zoom when mouse button released.

But I see a complexity in how to design the proportionality of panning/scrolling across the image at 100%. For very large images, one's mouse might fall off the pad.

It would be important for a user to be able to scroll from margin to margin (while at 100% - ie. LMB down) without lifting/repositioning the mouse.

Also, what happens if the image is already at 100% (or some other zoom ratio)? Maybe the opposite behavior might be useful in that circumstance: if the image is already zoomed, maybe pressing the LMB would zoom out... displaying a cross-hair/zoom marque on the full image and allowing the user to reposition it, then release the LMB and return to 100% at the new location.

Also, it occurs to me that only 100% is unusually limiting. Suppose a setting in Options for the user to select the "instant zoom" level, with XnView defaulting to 100%, but offering other levels...

Yes,
Toggeling between fit to window and x % in full screen (is better than 100% in some cases) LMB down.
And scrolling middle mouse bouton for next or previous image in full screen too.

This is a "ergonomic behavior" in this mode.

oops66 wrote:And scrolling middle mouse bouton for next or previous image in full screen too.

Well, that might be "un-ergonomic" for me! I use the wheel exclusively to zoom...

The following "ergonomics" might work well for me:

- View an image
- Zoom in or out (I use the wheel)
- Press & hold LMB
- XnView initially zooms to 100% or the user-set default secondary zoom %
- Roll the mouse wheel to set a new "secondary" zoom %
- Release LMB
- Image returns to initial view % (before pressing LMB)
- Scroll around in the image, whatever
- Press & hold LMB
- XnView zooms to most recent secondary zoom %

This procedure adds the ability to dynamically set and retain the "secondary" zoom level that results frrom LMB click & hold. This approach would allow a user to click & hold the LMB to zoom out, too, if they wished. Very useful for large images!

Using this method one could view and set any combination of two alternate (primary/secondary) zoom levels directly in the image via mouse interaction. Such as:

Fit to Window -> 100%
Fit to Window -> 50%
600% -> 50%
100% -> Fit to WIndow
etc...

An issue: what is the domain of persistence for the secondary zoom level? Is it reset to the default when moving to the next image, or is it retained?

-->JohnFredC
Full screen mode is only(mostly) for viewing, then :
Toggeling between fit to window and x % in full screen - LMB down.
And scrolling middle mouse bouton for next or previous image in full screen too.
Is pertinent !

In your case,maybe the appropriate mode for your suggestion is the view mode (not the full screen mode) no ?

Regardless of any changes to the mouse, I'd still be grateful if the / key was changed to a toggle as well. It'd be so much easier to use on laptops, without breaking existing functionality. (The menu item probably shouldn't be a toggle, but that's up to you.)